/* gzguts.h -- zlib internal header definitions for gz* operations
 * Copyright (C) 2004, 2005, 2010, 2011, 2012 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

#ifdef _LARGEFILE64_SOURCE
	#ifndef _LARGEFILE_SOURCE
		#define _LARGEFILE_SOURCE 1
	#endif
	#ifdef _FILE_OFFSET_BITS
		#undef _FILE_OFFSET_BITS
	#endif
#endif

#ifdef HAVE_HIDDEN
	#define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
#else
	#define ZLIB_INTERNAL
#endif

#include <stdio.h>
#include "zlib.h"
#ifdef STDC
	#include <string.h>
	#include <stdlib.h>
	#include <limits.h>
#endif
#include <fcntl.h>

#ifdef _WIN32
	#include <stddef.h>
#endif

#if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
	#include <io.h>
#elif defined(__GNUC__)
	#include <unistd.h>	// SRS - For explicit declaration of lseek, read, write, close
#endif

#ifdef NO_DEFLATE       /* for compatibility with old definition */
	#define NO_GZCOMPRESS
#endif

#if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
	#ifndef HAVE_VSNPRINTF
		#define HAVE_VSNPRINTF
	#endif
#endif

#if defined(__CYGWIN__)
	#ifndef HAVE_VSNPRINTF
		#define HAVE_VSNPRINTF
	#endif
#endif

#if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
	#ifndef HAVE_VSNPRINTF
		#define HAVE_VSNPRINTF
	#endif
#endif

#ifndef HAVE_VSNPRINTF
	#ifdef MSDOS
		/* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
		but for now we just assume it doesn't. */
		#define NO_vsnprintf
	#endif
	#ifdef __TURBOC__
		#define NO_vsnprintf
	#endif
	#ifdef WIN32
		/* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
		#if !defined(vsnprintf) && !defined(NO_vsnprintf)
			#if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
				#define vsnprintf _vsnprintf
			#endif
		#endif
	#endif
	#ifdef __SASC
		#define NO_vsnprintf
	#endif
	#ifdef VMS
		#define NO_vsnprintf
	#endif
	#ifdef __OS400__
		#define NO_vsnprintf
	#endif
	#ifdef __MVS__
		#define NO_vsnprintf
	#endif
#endif

#ifndef local
	#define local static
#endif
/* compile with -Dlocal if your debugger can't find static symbols */

/* gz* functions always use library allocation functions */
#ifndef STDC
	extern voidp  malloc OF( ( uInt size ) );
	extern void   free   OF( ( voidpf ptr ) );
#endif

/* get errno and strerror definition */
#if defined UNDER_CE
	#include <windows.h>
	#define zstrerror() gz_strwinerror((DWORD)GetLastError())
#else
	#ifndef NO_STRERROR
		#include <errno.h>
		#define zstrerror() strerror(errno)
	#else
		#define zstrerror() "stdio error (consult errno)"
	#endif
#endif

/* provide prototypes for these when building zlib without LFS */
#if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
	ZEXTERN gzFile ZEXPORT gzopen64 OF( ( const char*, const char* ) );
	ZEXTERN z_off64_t ZEXPORT gzseek64 OF( ( gzFile, z_off64_t, int ) );
	ZEXTERN z_off64_t ZEXPORT gztell64 OF( ( gzFile ) );
	ZEXTERN z_off64_t ZEXPORT gzoffset64 OF( ( gzFile ) );
#endif

/* default memLevel */
#if MAX_MEM_LEVEL >= 8
	#define DEF_MEM_LEVEL 8
#else
	#define DEF_MEM_LEVEL  MAX_MEM_LEVEL
#endif

/* default i/o buffer size -- double this for output when reading */
#define GZBUFSIZE 8192

/* gzip modes, also provide a little integrity check on the passed structure */
#define GZ_NONE 0
#define GZ_READ 7247
#define GZ_WRITE 31153
#define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */

/* values for gz_state how */
#define LOOK 0      /* look for a gzip header */
#define COPY 1      /* copy input directly */
#define GZIP 2      /* decompress a gzip stream */

/* internal gzip file state data structure */
typedef struct
{
	/* exposed contents for gzgetc() macro */
	struct gzFile_s x;      /* "x" for exposed */
	/* x.have: number of bytes available at x.next */
	/* x.next: next output data to deliver or write */
	/* x.pos: current position in uncompressed data */
	/* used for both reading and writing */
	int mode;               /* see gzip modes above */
	int fd;                 /* file descriptor */
	char* path;             /* path or fd for error messages */
	unsigned size;          /* buffer size, zero if not allocated yet */
	unsigned want;          /* requested buffer size, default is GZBUFSIZE */
	unsigned char* in;      /* input buffer */
	unsigned char* out;     /* output buffer (double-sized when reading) */
	int direct;             /* 0 if processing gzip, 1 if transparent */
	/* just for reading */
	int how;                /* 0: get header, 1: copy, 2: decompress */
	z_off64_t start;        /* where the gzip data started, for rewinding */
	int eof;                /* true if end of input file reached */
	int past;               /* true if read requested past end */
	/* just for writing */
	int level;              /* compression level */
	int strategy;           /* compression strategy */
	/* seek request */
	z_off64_t skip;         /* amount to skip (already rewound if backwards) */
	int seek;               /* true if seek request pending */
	/* error information */
	int err;                /* error code */
	char* msg;              /* error message */
	/* zlib inflate or deflate stream */
	z_stream strm;          /* stream structure in-place (not a pointer) */
} gz_state;
typedef gz_state FAR* gz_statep;

/* shared functions */
void ZLIB_INTERNAL gz_error OF( ( gz_statep, int, const char* ) );
#if defined UNDER_CE
	char ZLIB_INTERNAL* gz_strwinerror OF( ( DWORD error ) );
#endif

/* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
   value -- needed when comparing unsigned to z_off64_t, which is signed
   (possible z_off64_t types off_t, off64_t, and long are all signed) */
#ifdef INT_MAX
	#define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
#else
	unsigned ZLIB_INTERNAL gz_intmax OF( ( void ) );
	#define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
#endif
